Rhythm and timing information play a critical role in speech perception, especially in noisy listening situations. Training that targets temporal processing may therefore present an effective way to improve speech perception in noise. Indeed, musicians outperform their non- musician peers in the perception of speech in noise, and preliminary data indicate this advantage may be mediated by musicians' superior rhythm skills. The long-term goal is to understand the role of temporal processing in human communication and how it is shaped by experience. The objective is to identify neural and behavioral aspects of temporal processing that are both important for speech-in-noise perception and enhanced in musically-trained subjects. The central hypothesis is that speech-in-noise perception involves the detection of complex temporal patterns as well as precise neural timing across multiple timescales. Further, experience with complex rhythms during musical practice strengthens the ability to extract complex temporal patterns in speech. The rationale for the proposed research is that understanding how distinct aspects of temporal processing contribute to speech-in-noise perception across a range of musical expertise will advance our understanding of how timing information guides human communication through sound, and how everyday communication skills might be strengthened by rhythm-based training. The proposed study will test this hypothesis by pursuing two specific aims: 1) Identify the contribution of temporal processing to speech-in-noise perception and 2) Determine which aspects of temporal processing are strengthened by musical experience. An innovative combination of neural and behavioral measures will be used to evaluate temporal processing across multiple timescales. Neural responses to speech sounds will be recorded and filtered to evaluate neural timing precision in encoding of three different frequency ranges: fast-changing consonant characteristics, the speech envelope and the syllable rate. Behavioral measures of rhythm perception and production will use non-speech stimuli containing simple and complex rhythm patterns as well as music, allowing the assessment of fundamental temporal processing as well as the integrated perception of ecologically valid sounds. The proposed research is significant because it has the potential to identify key metrics and biomarkers of temporal processing that could aid in the diagnosis of communication difficulties, as well as guiding the development of more effective rhythm-based treatment and training strategies.